import math
x1,y1,x2,y2 = map(float, input().split())
dist = math.sqrt((x2-x1)**2+(y2-y1)**2)
print("%.6f" % (dist)) import math math x1,y1,x2,y2 = map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 dist = math.sqrt((x2-x1)**2+(y2-y1)**2) dist math.sqrt((x2-x1)**2+(y2-y1)**2) math.sqrt math sqrt (x2-x1)**2+(y2-y1)**2 (x2-x1)**2 x2-x1 x2 x1 2 (y2-y1)**2 y2-y1 y2 y1 2 print("%.6f" % (dist)) print "%.6f" % (dist) "%.6f" dist x1,y1,x2,y2 = map(float, input().split()) map(float, input().split()) x1 y2 = map(float, input().split()) map(float, input().split()) y2 y1,x2,y2 = map(float, input().split()) map(float, input().split()) y1 x2,y2 = map(float, input().split()) map(float, input().split()) x2 dist = math.sqrt((x2-x1)**2+(y2-y1)**2) math.sqrt((x2-x1)**2+(y2-y1)**2) dist
import math
x1,y1,x2,y2 = map(float, input().split())
dist = math.sqrt((x2-x1)**2+(y2-y1)**2)
print("%.6f" % (dist))